1. Field of the Invention
The present invention relates to a temperature setting method of a thermal processing plate, a computer-readable recording medium recording a program thereon, and a temperature setting apparatus for a thermal processing plate.
2. Description of the Related Art
In a photolithography process in manufacturing, for example, a semiconductor device, for example, a resist coating treatment of applying a resist solution onto a wafer to form a resist film, exposure processing of exposing the resist film into a predetermined pattern, heating processing of accelerating the chemical reaction in the resist film after exposure (post-exposure baking), and developing treatment of developing the exposed resist film are performed in sequence, so that the series of wafer processing forms a predetermined resist pattern on the wafer.
For example, the heating processing such as the above-described post-exposure baking is usually performed in a heating processing apparatus. The heating processing apparatus includes a thermal plate for mounting and heating the wafer thereon. The thermal plate has a heater embedded therein which generates heat by power feeding, and the heat generated by the heater adjusts the thermal plate to a predetermined temperature.
The thermal processing temperature in the above-described heating processing greatly affects the line width of the resist pattern to be finally formed on the wafer. Hence, to strictly control the temperature within the wafer during heating, the thermal plate of the above-described heating processing apparatus is divided into a plurality of regions, and an independent heater is embedded in each of the regions to adjust the temperature for each of the regions.
It is known that if the temperature adjustment for all of the regions of the above-described thermal plate is performed at the same set temperature, the temperature may vary within the wafer on the thermal plate, for example, due to the difference in thermal resistance between the regions, eventually resulting in variations in the line width of the resist pattern. For this reason, a temperature correction value (a temperature offset value) is set for each of the regions of the thermal plate to finely adjust the in-plane temperature of the thermal plate (Japanese Patent Application Laid-open No. 2001-143850).
Since an optimal temperature correction value for the above-described thermal plate varies depending on the apparatus state and processing environment, the set value needs to be changed as necessary. The change of the setting of the temperature correction value has been usually performed by an operator performing the line width measurement of the resist pattern and making judgment according to his/her experience and knowledge in consideration of data of the line width measurement results. Thereafter, the timing to change the setting of the temperature correction value is influenced by experience, knowledge, and judgment of each operator, causing variations. As a result, different operators might or might not perform change the temperature correction value even for the same line width measure result, which has also caused variations in the set value of the temperature correction value, eventually resulting in variations also in the line widths of the resist pattern.